Modern automatic dishwashers generally provide an energy saving drying option which permits the user to select heated drying or non-heated drying. When operating in the heated drying mode the heating element is energized during the timed drying cycle to speed up the drying process for the just-washed dishes. In the non-heated drying mode, the heating element is not heated during the drying cycle. In dishwashers known in the art, this option is provided by simply placing a user-actuable option selection switch in series with the heating element and the cam-actuated switch. The timer control cam which actuates the heater switch operates the same way regardless of which option is selected to close the heater cam switch at the beginning of the dry cycle. To select heated drying, the user closes the option selector switch and the heater is energized under control of the timer. To select the non-heated drying option, the user opens the option selection switch, preventing energization of the heater during the drying cycle even though the heater control switch is closed at the beginning of the drying cycle.
This conventional approach provides satisfactory results. However, it requires the addition of a manually operable switch capable of handling current on the order of 10 amps. Additionally, such an arrangement requires that additional switches be employed to bypass the option selection switch if it is desired to energize the heating element during the wash cycles independently of which dry cycle option is selected.
It is desirable to provide an electromechanical timer for appliances which enables the user, at his option, to selectively inhibit the control cam without adding additional external switches to the control circuit.
It is therefore an object of the present invention to provide an electromechanical timer for appliances, such as dishwashers, which permits the user to selectively inhibit switch actuation by the heater control cam to prevent heater energization when the non-heated drying cycle is selected without the need for additional switches.
It is a further object of the present invention to provide an electromechanical timer for appliances such as dishwashers in which the primary switch actuating cam is inhibited by selectively transferring cam actuation to an auxiliary cam which permits actuation of the timer by the primary cam during the wash cycle and by the secondary cam during the drying cycle.